Check whether we got a nil interface pointer back (#34)

VERSION

@@ -1 +1 @@
-0.2.4
+0.2.6

nrpe_exporter.go

@@ -99,17 +99,20 @@ func (c *Collector) Collect(ch chan<- prometheus.Metric) {
 			return
 		}
 		conn, err = openssl.Dial("tcp", c.target, ctx, openssl.InsecureSkipHostVerification)
+		if conn == (*openssl.Conn)(nil) || err != nil {
+			level.Error(c.logger).Log("msg", "Error dialing NRPE server", "err", err)
+			return
+		}
 	} else {
 		d := net.Dialer{}
 		conn, err = d.Dial("tcp", c.target)
+		if err != nil {
+			level.Error(c.logger).Log("msg", "Error dialing NRPE server", "err", err)
+			return
+		}
 	}
 	defer conn.Close()
 
-	if err != nil {
-		level.Error(c.logger).Log("msg", "Error dialing NRPE server", "err", err)
-		return
-	}
-
 	cmdResult, err := collectCommandMetrics(c.command, conn, c.logger)
 	if err != nil {
 		level.Error(c.logger).Log("msg", "Error running command", "command", c.command, "err", err)

vendor/modules.txt

@@ -14,6 +14,8 @@ github.com/canonical/nrped/common
 # github.com/cespare/xxhash/v2 v2.1.1
 ## explicit; go 1.11
 github.com/cespare/xxhash/v2
+# github.com/davecgh/go-spew v1.1.1
+## explicit
 # github.com/go-kit/kit v0.9.0
 ## explicit
 github.com/go-kit/kit/log